THE SOLAR SYSTEM

1. THE SOLAR SYSTEM Chapter 30

2. PLANET MOTION – 30.1 A. Models of the Solar System 1. Geocentric model a. Please Define Geocentric Model: Earth-centered model of the Solar System.

3. What does “Planasthai” mean? To wander, and our word Planet comes from this meaning.

4. Who proposed this Geocentric Model? The Greek philosopher Ptolemy.

5. d. Geocentric modifications 1.) What were the Problems associated with this Geocentric Model? The Planets in our Solar System periodically appeared to move in a retrograde motion or move backwards as compared to the background of distant stars.

6. Heliocentric model a. Please Define Heliocentric Model: Sun-centered model of the Solar System.

7. Who proposed this Heliocentric Model? Nicholas Copernicus, a Polish astronomer in 1543.

8. c. Galileo 1.) What did Galileo discover? a.) The Italian astronomer, Galileo Galilei, discovered evidence to support Copernicus’ heliocentric model, by observing that Venus had phases like the Moon and these phases could only be explained if Venus orbited the Sun and passed between Earth and the Sun.

9. b. Galileo also discovered the four largest moons of Jupiter; Ganymede, Callisto, Io, and Europa.

10. Understanding the Solar System 1. What did Johannes Kepler discover? a. Planets move around the Sun in ellipses rather than in perfect spheres.

11. b. Kepler also found that the planets are located at different orbital distances relative to the Sun.

12. Classifying the planets a. What are Terrestrial Planets? Planets are similar to Earth in size, structure, and composition. They are Mercury, Venus, Earth, and Mars.

13. What are Jovian Planets? The giant planets like Jupiter which is composed mostly of gas. They are Jupiter, Saturn, Uranus, and Neptune.

14. What are Inner Planets? Planets that are classified by location. The Inner Planets would be the planets between the Sun and the Asteroid belt. They are Mercury, Venus, Earth, and Mars.

15. What are Outer Planets? Planets between the Asteroid belt and the Kuiper Belt. They are Jupiter, Saturn, Uranus, Neptune, Pluto, Eris, and Sedna.

16. What are Superior Planets? Planets between the Earth and the Sun. They are Mercury, and Venus.

17. What are Inferior Planets? Planets that are beyond Earth’s orbit. They are Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, Eris, and Sedna.

18. Origin of the solar system a. Objects in the our Solar System as viewed from the North Star move in which direction? Counterclockwise around the Sun.

19. Other Solar Systems 1. Please Define Extrasolar planets: Planets in orbit around stars other than the Sun.

20. 2. As of April 2014, how many Extrasolar planets exist? About 1000.

21. THE INNER PLANETS – 30.2 A. Planets Near the Sun 1. Mercury a. Please Describe Mercury: Mercury is second smallest planet in our Solar System, Pluto is the smallest. Mercury revolves around the Sun in 88 days.

22. What is Mercury’s Interior like? Mercury has a large inner iron core surrounded by solid rock.

23. Mercury’s surface 1. What is Mercury’s surface like? Mercury is covered with deep craters and steep cliffs up to 3 km high.

24. Is there an atmosphere around Mercury? Mercury has no atmosphere because of its proximity to the Sun. The temperature on Mercury ranges from 430oC to -170oC.

25. Venus a. Please Describe Venus: Venus is the second closest planet to the Sun. It is blanketed with a thick dense atmosphere, 92 times more thick than Earth’s atmosphere. Its atmosphere is mostly CO2 and its surface has mountains, valleys, and inactive volcanoes.

26. Why is Venus sometimes referred as Earth’s Sister Planet? Venus has almost the same mass and size as planet Earth.

27. The greenhouse effect 1.) What gas in Venus’ atmosphere cause the planet to be so hot? Carbon dioxide. 2.) What is the temperature on the surface of Venus? Between 450oC and 475oC.

28. Earth a. Please Describe Earth: Earth is the third planet from the Sun and the temperatures on Earth allow water to exist as a solid, liquid, and gas on its surface. Its atmosphere is 78% nitrogen, 21% oxygen, and trace of other gases.

29. What is Earth’s average temperature? Earth’s average temperature is 15oC.

30. What does Ozone or O3 in Earth’s atmosphere protect us from? From the intense ultraviolet rays from the Sun.

31. d. Life on Earth • Mars a. Please Describe Mars: Mars is the fourth planet from the Sun. It is called the “Red” planet because of the presence of iron oxide minerals in its rock.

32. What is Mars’ axis tilt? Mars rotates on a tilted axis at an angle of 25o.

33. c. What is Mars’ average temperature? Mars’ average temperature is -60oC.

34. Mars’s atmosphere Mars’ has a very thin atmosphere, composed mostly of CO2, nitrogen, argon, oxygen, and water vapor. The surface temperature of Mars ranges from -140oC to 20oC.

35. Martian moons 1. What are the two moons of Mars? a.) Phobos which means fear, is the closest moon and is heavily cratered. b.) Deimos which means panic, is the farthest moon and is also heavily cratered.

36. Was Mars once wet? Surface features like gullies and layered sediments suggest evidence that liquid water was once present on Mars.

37. NASA on Mars 1. What is the valley of Mars called? The “Valles Mariners” is so large that it could stretch from San Francisco to New York City if on Earth.

38. What is Olympus Mons? An extinct Volcano that is largest known volcano in our Solar System. This volcano is over three times higher than Mount Everest.

39. Olympus Mons

40. The Viking probes • Global Surveyor, Pathfinder, and Odyssey a. What did they find in Mars’ crust? They showed that water is frozen within Mars’s crust and is in the form of permafrost.

41. Mars Exploration Rover mission a. What did this Rover mission find? The found round concretions of hematite deposits and scientists speculate that this concretions were made in standing water on the surface of Mars.

42. Martian Meteorites • THE OUTER PLANETS – 30.3 A. Planets Far from the Sun 1. Jupiter a. Please Describe Jupiter: Jupiter is the fifth planet and the largest planet from the Sun and contains more mass than twice the mass of all of the other planets combined. It is composed of about 90% hydrogen, 10% helium, and a trace of ammonia, methane, and water vapor.

43. Jupiter

44. The Voyager probes and Galileo • Jupiter’s Moons 1. How many moons does Jupiter have? Jupiter has 63 known moons. Many are small, rocky bodies that could be captured asteroids.

45. Please Describe Ganymede: Ganymede is the largest moon in the Solar system. Ganymede is larger than Mercury or Pluto. This moon is composed of ice and rock.

46. Please Describe Io: Io is the closest moon to Jupiter. Because of this, Io experiences a constant tug-of-war between the gravities of Jupiter and Europa. This heats up Io’s interior and causes it to be the most volcanically active object in our Solar System. Io’s surface looks like a Pizza.

47. Please Describe Europa: Scientists believe that Europa has subsurface oceans of liquid water. They even believe that Europa could hold more than twice the amount of water that Earth’s oceans hold.

48. Please Describe Callisto: Callisto is a little smaller than Ganymede. Callisto is cratered throughout its entire surface and has a series of concentric rings.

49. 2. Saturn a. Please Describe Saturn: Saturn is the sixth planet from the Sun and is the second largest planet. It has the lowest density and composed mostly of hydrogen and helium with trace amounts of methane, ammonia, and water vapor.

50. Saturn’s rings 1. What is the composition of the rings? Saturn’s rings are made of particles of water-ice, and small rocks.